houseboat outboards

[ATR]

Hello! Just found a new source of good advice, having caused severe heartburn on several other forums.

We're building a home-made houseboat that we hope to have motors on by late summer, maybe. The project has been underway for about 3 years. Its hulls were constructed in sections, assembled in the water, and now we're in the midst of building a house on top of the deck. It is 50' long, 16'beam, 3.5' freeboard, 12" draft, plywood copper-clad flat-bottom pontoons. Boatsy neighbors laugh at its over-sturdiness. When finished, it may weigh as much as 28,000 pounds. Its hull speed should be about 9 knots. We're figuring to mosey along the ICW and quiet rivers with outboards. Calculations suggested 45hp high thrust motors ought to be plenty to push us at hull speed, so we added a fudge factor and decided 60hp Mercury Big Foots ought to do it. Then we began to hear many horror stories about Merc service and support. Our little town has an independent mechanic who sells and services Honda and Suzuki. Down the road 35 miles, we can get E-tecs and those Mercs. We can also find Yamahas not too far away.

So, voices of experience? What brand would you recommend for the most trouble-free engines available? We're not going to go fast, will need to swing fairly large, fairly flat props- We'll try 14/11 to start with. And they'll have to be installed in the water, because there's no way to haul this monstrosity out around here.

Thanks for not laughing out loud.... It's a little late to start over on something smaller for a first effort.

 

[thenotsofreeboat]

Re: houseboat outboards

I am not a expert nor am I a wise man

but I would say any of those motors should do just about as good as the other's as long as they are maintained.

I think you may be a little under powered if you are just use one though. I mean this thing is massive by your description, and i in no way can see a 45 HP engine pushing this rig at 1 never mind 9 knots. I have a 75HP engine on a boat that is as long as your beam and it pushes it 25-35 MPH and it only weights 12-1500 pounds. It seems to me anything you put on there is going to be stressed pushing that big of boat around so i wouldn't worry much about the life of an engine. I think you will go through them like crazy. But once again i am not an expert.

We need pictures of this, If this thing works out you might have an internet community committed to seeing this thing run the open water.

 

[CATransplant]

Re: houseboat outboards

You're asking an awful lot out of a couple of 60hp outboards. I believe if I were you, I'd be looking at an inboard diesel for a 14-ton houseboat if you actually plan to cruise with it. A big one, at that.

On a river big enough to run that thing, I don't think 120hp will even make way upstream, nor control the boat properly heading downriver.

I'd do a little more study on it.

 

[External Combustion]

Re: houseboat outboards

No worries about your horsepower ATR. The world ships most of its goods on one horse per ton to attain hull speed. Two horse per ton will get you 1.34 times the hull speed with a good layout. Let's just say you have a barge with punt ends you will get your 9 mph (not 9 knots though) with four horse per ton which will be 50 horse.

Figure in some wind fighting ability and your twin 45's will do fine. Just remember that a houseboat has the aerodynamics of a brick and you will have to tie up in moderate winds. The old paddlewheeel steamers did also.

My steamboat usually uses 8 hp to push it's 11,000lb weight (normally laden) at 7 to 8 mph depending on the wind. We swing a 24" diameter prop so wind is not much in the equation. We once pulled twenty tons at 4 knots with six effective horse.

Most folk do not have experience with true displacement craft and they can not believe how little power it takes to get to hull speed.

The largest prop you can swing and still have the engine up to the correct rpm at WOT is the way to go.

Understand I am not an outboard motor man, but some good advice that I have garnered here has taught me not to worry about the longivity of a correctly propped and maintained outboard. I understand that the BigFoot series and others offer greater reductions to drive the prop and that is how you will get greater efficiency at displacement speed.

The diesel would be a better idea for economy, but I also understand the space restraints and how it would increase the draft unless you went to a tunnel hull.

Keep us posted and get some pictures if you can. I for one am very interested. You will have to take my sanity into consideration though, after all I think that internal combustion is a passing fad!

 

[JB]

Re: houseboat outboards

Back in the 80s I lusted for an outboard houseboat. It was called the SeaCamper and it was towable on it's own, built-in, retractable wheels (landing gear?). I think it was 24'X8' as an outboard and 26'X8' and an I/O. It had a planing hull and typically used a pair of JohnnyRude V4s.

Now to your displacement hull housebarge. I have no idea how to calculate displacement speed or power needed to reach displacement speed, but I will concede that you have probably got good answers to both, for still water. The ICW and its tributary rivers are not still. Think about that.

Any of the engines you are considering will do as well as any other, except you have exactly the job to do that Hi-thrust and BigFoot were designed for, so I would limit consideration to engines with big, low pitch props.

Frankly, the idea of piloting a 16' wide barge on the Dania Cutoff during a tide change scares heck out of me.

 

[JCF350]

Re: houseboat outboards

Never mind adding motors just Tug it. You'll have more control in any given situation for something like that.

 

[ATR]

Re: houseboat outboards

Thank you for your thoughtful replies...
For you curious/incredulous ones, more than you want to know can be found at http://reiheld.home.mchsi.com/boat.htm

The interior is arranged bassackwards from most houseboats we've seen, with inside helm in a small multipurpose sitting room, office, guest room forward. The main bedroom and head lie amidships across a passageway from each other, and a rather large salon/galley/dining room is astern, opening out on to generous back deck, which may eventually be screened. Each segment of the pontoons is watertight, and is accessible through a good-sized hatch. A 2-foot walkway goes around the main deck outside the cabin, and a stairway goes up over and back down the starboard 'bumpout' for the head, for quick access to the top deck from either direction. The thing has been in the water for more than two years now, and we're pleased with how it has held up, and how well the copper sheeting works to repel bottom-fouling flora and fauna.

We have a very long way to go yet, especially as the ostensibly retired boatbuilder keeps going back to work, part-timing in a non-nautical profession. Plus, the boat work is mostly solo, to ensure the domestic tranquility. It's essentially a retirement project to keep him out from underfoot, but we're already looking forward to the extra guestroom space at home, and a way to go exploring in comfort.

On our immediate still-to-do list are exterior painting, finishing the top deck, installing windows. And of course, hanging the motors and installing the controls and steering apparatus for both topside and inside helms. Interior finishing, galley, plumbing, electrical, hvac, and that sort of thing can happen any time after those essentials, and at leisure. And then, too, I'd really like to put enough solar panels and batteries on the thing to run the basics, so as to minimize generator use while swinging in some serene backwater cove, to the extent our Carolina humidity will let us avoid A/C. So that in an overly large nutshell is what we're up to.

We expect to put one outboard on the stern of each pontoon, which should give us decent directional control, we hope (!), understanding, of course, the limitations of slow boats and fast, rough water or hard wind. We'd have to pick our times, tides, and weather fairly carefully, especially until we get the hang of good control. But we ain't goin' nowhere very fast even under the most ideal conditions, got nowhere we got to be, at least in theory.

The nagging question is, which brand of outboard might we expect to be the most durable, best supported, most reliable, and so forth.

Thanks again, y'all. All feedback is most welcome.
Amelia

 

[JCF350]

Re: houseboat outboards

We expect to put one outboard on the stern of each pontoon, which should give us decent directional control, we hope (!), understanding, of course, the limitations of slow boats and fast, rough water or hard wind. We'd have to pick our times, tides, and weather fairly carefully, especially until we get the hang of good control. But we ain't goin' nowhere very fast even under the most ideal conditions, got nowhere we got to be, at least in theory.

I was going to say nevermind my earlier comment but since you haven't placed them yet. how about fore and aft mounted.

The nagging question is, which brand of outboard might we expect to be the most durable, best supported, most reliable, and so forth.

Your gonna get into personal opinions on this subject. Any of the major makers will do if there is one built for your application get it. They all break at one time or another and service is going at what ever dealer your at when you need it. Manufacturer intervention takes a bit.

 

[tashasdaddy]

Re: houseboat outboards

interesting boat, way over my head.

 

[JCF350]

Re: houseboat outboards

Judging from your pictures it looks like your ending up with a bit more draft than originally intended, but that's not a bad thing your case.

Nevermind the fore and aft engines too.

Need big props.

 

[JCF350]

Re: houseboat outboards

Mounting the engines in the water? If it were my job, not a chance. Wouldn't want to sling the boat either, but there a yards around with "syncro-lifts" (small and large units). It would only need to be on the lift long enough to mount the engines properly. The rest of the rigging could be done later

 

[ATR]

Re: houseboat outboards

Yep, more draft than we first figured. That's because we got tired of building pontoon sections, and were eager to cut to the chase. The boat has thus wound up 8 feet shorter than when we initially figured the buoyancy- and hull speed. It's just as well. The price of copper subsequently went through the roof, too.

We're hoping to tow the thing over to a very nearby marina's launching ramp, then use a cherry-picker sort of contraption to drop the motors in place, and fasten them into pre-drilled mounting holes. Probably turn out to be harder than it sounds.

 

[tashasdaddy]

Re: houseboat outboards

i suggest a weekday for mounting, and a boom truck for managing the motors, the ramps get extremely slippery, and trying to handle a motor on it can be extremely dangerous.

 

[JCF350]

Re: houseboat outboards

Probably not harder. Even using a template things need to be checked and measured before drilling. Mostly ease of access.
Safety issue would be footing (as in staying on ones own) on the ramp as you can always use air drills.

You could use shallow water and lower the engines from the boat however. As always local boat traffic can mess that up, but the motor will move with the boat instead the motor just hanging there and the boat moving on you. Need lookouts for this.

 

[72SideWinderSS]

Re: houseboat outboards

Dry dock the thing. To install the motors.

 

[ATR]

Re: houseboat outboards

Would if we could, Jimmy, but we're MANY miles from the nearest lift big enough to haul this thing out,- it'd be an all-day tow, at least, and afraid it's not designed for that, anyway. We are way out in the sticks, or swamp as the case may be. This part of the world is beautiful, but lacking certain amenities. We're stuck. But it should be interesting....you're welcome to come point and laugh. Or gasp in horror.

 

[External Combustion]

Re: houseboat outboards

Well, ATR you have the advantage of a well built hurricane deck (roof) that will support a great load. Have His Excellency rig a long 4X4 supported well by the hurricane deck beams out over the pontoons where the engines will be mounted and rig a two to four ton cable comealong to it. The four ton comealong will make finer adjustments easier. Back your boat up to the wharf and wheel the engines out to the boat. Hook the comealong to the engine, ratched away and place the engine brackets on the hull at your leasure. Repeat for the opposite side.

Primitive, but effective and most important very controlable with little physical exertion. You don't want to ask how I know!

An air drill would be the safest and the cat's meow, but a good cordless drill or even (gasp) a hand drill will work if you keep the electrics dry. I know manual labor is eschewed these days but hey, I'm old fashioned!

Make sure you have bolts available that you think are too short, a set that you think are too long and the set that you think are just right. Murphey has a way of sneaking up on us all.

Boy, I wish I could be there to watch the fun. It would be nice not to have to pucker for myself for once!

Be safe now. Slow and steady beats fast and tragedy.

 

[Steve Mahler]

Re: houseboat outboards

I am surprised you are finding trouble getting someone to mount the motors. Jeepers, first of all we arent talking about 200hp big blocks. Second, in my marina we recently pulled and reinstalled two chrysler small block V8s in a 60s house boat using a backhoe with an extended boom. The bucket was removed to increase lift capacity...it was close, but they got the boat close enough to shore to pull it off...

You need to find someone with some suthern inginuity

 

[ATR]

Re: houseboat outboards

Trouble with Southern Ingenuity- (Engine-uity?) is that our good ole boys ain't in any hurry to exercise it-- or anything else. We just seem to be in a bigger hurry than most people 'round heah, even at our snail's pace. I 'spect they'll git back to us, when the stars line up right, or thar ain't nuthin better to do, or the checkbook looks thin.